Device for connecting an active substance container to an injection nozzle in a device used to inject said active substance

ABSTRACT

The invention relates to an injection device which may or may not be equipped with a needle, comprising an injection nozzle and a tube which is intended to receive the active substance to be injected, whereby the tube is fixed to the nozzle using connecting means. The inventive device is characterized in that the aforementioned connecting means comprise at least three identical bosses which are solidly connected to the nozzle. Moreover, each of said bosses comprises an inclined part which terminates in a flange, said flange co-operating with a collar which is formed on the tube and acts as a backstop for the tube when the latter is connected to the nozzle.

The technical field of the invention is that of prefilled and disposableinjection devices which may or may not be equipped with a needle andwhich function with an energy source, for example a gas generator, andare used for intradermal, subcutaneous and intramuscular injections ofliquid active substance for therapeutic use in human or veterinarymedicine.

The active substance is composed of a liquid of greater or lesserviscosity, a mixture of liquids, or a gel. The active substance can alsobe a solid dissolved in a suitable solvent for injection or can be apowdered solid in suspension at a certain concentration in a suitableliquid. The particle size of the active substance must then becompatible with the diameter of the conduits so as to avoid blockingthem.

An injection device comprises in a known manner, for example as inpatent application FR 2 815 544 (equivalent of WO 02/34317), amechanical assembly and a pharmaceutical assembly. The mechanicalassembly is composed in particular of a mechanism for actuating thedevice and of an energy source, formed for example by a pyrotechnic gasgenerator and intended for injecting the active substance through thepatient's skin. The pharmaceutical assembly comprises the liquid activesubstance. The active substance is generally placed in a tube which isthen intended to be inserted into the mechanical assembly. The twoassemblies are generally assembled separately, the filling of the tubewith the active substance having to be precisely controlled and carriedout in an enclosed environment in order to avoid impurities infiltratinginto the tube and contaminating the active substance. It is especiallynecessary that no impurities settle in the zones through which theactive substance is to flow. To avoid infiltration of these impuritiesinto the tube, the tube can be fitted, during production of thepharmaceutical assembly, on the nozzle for injecting the activesubstance and it can be pressed against said nozzle to create aleaktight connection between the two elements. The two elements, that isto say the tube filled with active substance and the injection nozzleconstitute the pharmaceutical assembly. After the two elements of thepharmaceutical assembly have been joined together and the tube has beenfilled with the active substance, and before the pharmaceutical assemblyis fitted on the mechanical assembly, a certain length of time mayelapse during which the pharmaceutical assembly is transported andstored in an unenclosed environment, for example a warehouse. Duringthis period, it is therefore necessary to maintain a perfect connectionbetween the injection nozzle and the tube and good pressing of the tubeagainst the injection nozzle in order to avoid penetration of impuritiesinto the tube. In order to maintain a perfect connection between thenozzle and the tube, the nozzle must not be subjected to too muchmechanical stress when fixing it on the tube.

U.S. Pat. No. 6,132,395 discloses a needleless injection devicecomprising a container and a nozzle made of polycarbonate intended to befixed on the container formed by a glass tube. The nozzle is situated atone end of the tube and more particularly comprises four tabs whichextend the entire length of the tube and end in bosses which allow thenozzle to be clipped onto the tube. The tabs thus form a claw whichencloses the tube in order to fix the nozzle. In said patent, the nozzleis fixed directly by virtue of its tabs. The tabs bend outward along theentire length of the tube until the tube is completely enclosed. Whenthe nozzle is being clipped onto the tube, this unique mechanicalstressing of the tabs may create irreversible deformation of the tabs ifthey are made of a hard material such as polycarbonate, for example, andmay thus lead to a poor connection between the tube and the nozzle.

The object of the invention is therefore to maintain a perfectlyleaktight connection between the tube and the injection nozzle in orderto avoid penetration of impurities into the tube when the pharmaceuticalassembly is not yet fitted on the mechanical assembly to produce thecomplete needleless injection device.

This object is achieved by a device for injecting an active substancethrough a patient's skin, comprising in particular an injection nozzleand a glass tube intended to receive said active substance to beinjected, said tube being fixed to said nozzle with the aid ofconnecting means, the connecting means comprising at least threeidentical bosses which are integral with the nozzle, said bosses eachcomprising an inclined part which is terminated by a flange, said flangecooperating with a collar which is formed on the tube and is situated atone of the ends of the tube, said collar serving as an anti-returnelement for the tube when the latter is connected to the nozzle, saiddevice being characterized in that the bosses are connected to oneanother by connecting branches.

According to one particular feature, the connecting branches have aheight of 1.4 mm. According to the invention, the thickness and heightof the connecting branches are chosen so as to make the connectingbranches sufficiently flexible to lengthen and bend in the area of thebosses during clipping-on of the tube. In particular, the flexibility ofthe connecting branches allows each of the bosses to match the shape ofthe glass tube.

According to another particular feature, the bosses are supported by theconnecting branches, said connecting branches being made integral withthe nozzle by means of connecting blocks and being connected to oneanother so as to define a substantially circular crown whose diameter issubstantially equal to the external diameter of the collar of the tube.According to the invention, the geometry of the crown used for clippingthe tube onto the nozzle has been designed to better distribute thestresses exerted on the tube.

Thus, by virtue of the presence of the connecting branches supportingthe bosses, the deformation necessary for clipping the tube onto thenozzle is not limited to simple bending in the area of the bosses, butinstead simultaneously consists of a lengthening of the connectingbranches and a bending of these connecting branches in the area of eachof the bosses. The connecting blocks ensure the rigidity and blocking ofthe clip connection between the tube and the nozzle.

According to the invention, each of the bosses constitutes a point ofcontact between the nozzle and the tube.

According to one particular feature, the inclined part of the bosses isinclined in the direction of the nozzle and toward the inside of thenozzle. This inclined part makes it possible, particularly when the tubeis being clipped onto the nozzle, to guide the tube and gradually spreadapart the bosses in order to allow the collar of the tube to pass these.The degree of inclination of this inclined part must be designed tolimit as far as possible the force needed for spreading the bosses apartas the collar of the tube passes them.

According to another particular feature, each boss is inwardly curved,the bosses all being inscribed in a same circle whose diameter issubstantially equal to the external diameter of the collar of the tube.According to the invention, the force with which the tube is pressedagainst the nozzle is therefore not distributed, in the area of eachboss, on one contact point, but instead on a line or even on a surface.

According to another particular feature, the angle of opening defined bythe two segments joining the center of the circle to the ends of eachinwardly curved boss is between 17 and 23 degrees. According to theinvention, for each boss the greater the angle defined above, the betterwill be the distribution of the stresses on the glass tube.

According to another particular feature, the bosses are spaced apartfrom one another at regular intervals. The spacing of the bosses has tobe uniform in order to obtain a homogeneous distribution of the stresseson the tube.

According to another particular feature, the nozzle has a flat surface,the bosses being situated at a non-zero distance from said surface, thespace between the flange of the bosses and said surface substantiallycorresponding to the thickness of the collar of the tube.

According to another particular feature, the end of each of the bosseshas a rounded shape. The line of contact of each of the bosses with thetube is situated at the summit of the rounded part. The rounded partthus makes it possible to eliminate any sharp edge and thus limit anydamage to the glass tube.

According to another particular feature, the diameter of the circlewithin which the bosses are inscribed is 13.2 mm, and the rounded shapeof the bosses has a radius of 0.1 mm. According to the invention, thegreater the diameter of the circle, the more stable is the connection ofthe tube to the nozzle and the weaker the forces exerted on the glasstube.

According to one embodiment, each boss is supported by a rod which isfixed to the nozzle and is able to deform elastically.

According to a preferred embodiment of the invention, the nozzle, thebosses, the connecting branches and the connecting blocks are made asone piece.

According to one particular feature, the piece formed by the nozzle, thebosses, the connecting branches and the connecting blocks is made frompolycarbonate. According to the invention, the material constitutingthis piece must be able to satisfy a number of conditions. Inparticular, this material will have to be sufficiently hard to betraversed by the liquid active substance without deteriorating, and itwill have to be sufficiently flexible to be able to be clipped onto thetube. Moreover, this material will have to be approved for use in thefield of pharmacy and must not be aggressive with respect to glass so asnot to scratch and damage the tube.

According to a preferred embodiment of the invention, the injectiondevice is needleless and comprises, as energy source for injection ofthe active substance, a pyrotechnic gas generator.

The invention, with its characteristics and advantages, will becomeclearer from reading the description given with reference to theattached drawings, in which:

FIG. 1 depicts, in an exploded view, a needleless injection deviceaccording to the invention.

FIG. 2 depicts, in perspective, an injection nozzle used in theinjection device according to the invention.

FIG. 3 depicts, in perspective, a container intended to receive theliquid active substance for injection.

FIG. 4 depicts, in plan view, the injection nozzle shown in FIG. 2.

FIG. 5 depicts a longitudinal section, along line A-A, of the injectionnozzle shown in FIG. 4.

FIG. 6 depicts, in perspective, the container seen in FIG. 3, fitted onthe injection nozzle to form a pharmaceutical assembly.

FIG. 7 depicts a cross section through the pharmaceutical assembly seenin FIG. 6.

An injection device 1 according to the invention, as depicted in FIG. 1,has no needle and comprises a body (not shown) inserted under a cap 9for actuating the device 1, this cap being closed off by a stopper 10.The device 1 will, for example, have a compact form, the advantages ofwhich are more particularly described in Pat. No. FR 2 815 544.Actuation of such a device 1 by the patient, using the cap 9, is alsodescribed in patent FR 2 815 544. During the process of assembling thedevice 1, the body is intended to receive a plurality of elements. Thus,once assembled, the body comprises or delimits successively, fromupstream to downstream, an initiator device, for example a percussiondevice, a primer, and a pyrotechnic charge, these three elements forminga gas generator, a combustion chamber, a reservoir 5 containing a liquidactive substance to be injected, and an injection system.

According to the invention, the needleless injection device 1 comprisestwo main assemblies, namely a mechanical assembly and a pharmaceuticalassembly 2. These two assemblies are distinct because, in general, theyare produced separately, the construction of the pharmaceutical assembly2 requiring specific monitoring and very close attention in particularas regards the filling with the active substance 53.

The mechanical assembly comprises in particular the gas generator andthe mechanism for actuating the device according to the invention. Thepharmaceutical assembly 2 comprises the container 5 for active substance53 and the system for injection of the active substance 53.

The container 5 intended to receive the active substance 53 is shown inmore detail in FIG. 3. It is formed, for example, by a glass tube 50open at both ends. The tube 50 comprises a collar 54, 55 at each of itsends. At the end of the tube 50, each collar 54, 55 defines a flatannular surface 540, 550. The tube 50 is inserted into the body of thedevice 1 in such a way as to be connected, at its most upstream end, tothe combustion chamber of the device 1, and, at its most downstream end,to the injection system. The active substance 53 (FIGS. 6 and 7) is, forexample, held captive in the glass tube 50 between an upstream pistonplug 51 and a downstream piston plug 52 which are inserted into the tube50. The upstream 51 and downstream 52 piston plugs are made, forexample, of an elastomer-based deformable material.

According to the invention, the injection system comprises an injectionnozzle 3 through which the active substance 53 held in the container 5is injected. The injection nozzle 3 comprises a cylindrical component 30around which a thread 300 is formed so as to allow the nozzle 3 to bescrewed onto the body of the needleless injection device 1. Thecylindrical component 30 comprises a flat surface 301, forming a supportplane for the tube 50, perpendicular to the axis A1 (FIG. 5) of thenozzle, at the center of which surface a blind hole 302 is formed. Thecylindrical component 30 is traversed by a plurality of injectionchannels 303 along which the liquid flows at the time of injection. InFIG. 2, these channels 303 are three in number. They are formed parallelto the axis A1 of the nozzle 3, at the periphery of the blind hole 302formed on the cylindrical component 30. At the end of the injection, thedownstream piston plug 52 comes to sit in the blind hole 302, thusliberating the liquid active substance 53, which is then able to escapethrough the peripheral channels 303 communicating with the inside of thetube 50.

According to the invention, the nozzle 3 also comprises a crown 31 witha diameter substantially equal to the diameter of the cylindricalcomponent 30. This crown 31 is in the form of a circular band arrangedcoaxially with respect to the axis A1 of the nozzle 3, the surface ofsaid band being parallel to the axis A1 of the nozzle 3. This crown 31is situated at a defined non-zero distance from the cylindricalcomponent 30 and is connected to it by way of connecting blocks 32 onthe surface of the cylindrical component 30 near the outer edge of thecylindrical component 30. These connecting blocks 32 are, for example,three in number and distributed in a balanced way between the crown 31and the cylindrical component 30, that is to say at an angle of 60°relative to one another. Emerging from each block there is a rod 320,each rod 320 including, for example, an inclined part (FIG. 5) allowingthe tube 50 to be guided when fitting it onto the nozzle 3. Arrangedequidistantly between each block 32, that is to say offset 30° relativeto each of the blocks 32, the crown 31 comprises a boss 33. Each boss 33is elongate and inwardly curved following the curvature of the crown 31.The angle defined by the segments joining the center of the crown 31 toeach of the two ends of a boss 33 is, for example, between 17° and 23°and is preferably 20°. Each boss 33 is formed by a portion 330 (FIG. 2)inclined with respect to the surface defined by the band. This portion330 is inclined toward the inside of the nozzle 3 and in the directionof the cylindrical component 30 and is terminated by a flange 331. Thesummit or end of each of the bosses 33, defined as the connectingsurface between the inclined portion 330 and the flange 331, has arounded shape 332 (FIG. 5), with a radius equal to 0.1 mm, for example.The crown 31 has, for example, a diameter of 15 mm. The diameter of thecrown 31 at the top of the boss 33 is, for example, 13.2 mm. The heightof the band defining the crown is, for example, 1.4 mm. The thickness ofthe crown 31 is greater in the area of the blocks 32.

According to the invention, the tube 50 is intended to be fitted, at oneof its ends, onto the nozzle 3 in order to form the pharmaceuticalassembly 2. To do this, one of the ends of the tube 50 is clipped ontothe nozzle 3. The space defined between the crown 31 and the cylindricalcomponent 30 is substantially equal to the thickness of the collar 55formed at one end of the tube 50. This space is thus sufficient toaccommodate said collar 55. The tube 50 is inserted onto the nozzle 3 insuch a way that its axis substantially coincides with the axis (A1) ofthe nozzle 3.

When fitting the tube 50 on the nozzle 3, the tube 50 is first guided bythe rods 320 continuing the connecting blocks 32. The collar 55 situatedat the end of the tube 50 then follows the inclined portions 330 of thebosses 33. The degree of inclination of the inclined portions 330 of thebosses 33 has an impact on the force that has to be expended to spreadapart the bosses 33 and allow the collar 55 to pass. On continuing withfitting the tube 50, the collar 55 passes the summits of the bosses 33and comes to sit under the bosses 33. The annular surface 550 situatedat the end of the tube 50 is then held flat against the surface of thecylindrical component by way of the bosses 33. Each of the flanges 331of the bosses 33 constitutes an anti-return element against the movementof extraction of the tube 50 relative to the nozzle 3.

According to the invention, the connecting branches 34 (FIG. 4) definedby the parts of the crown 31 supporting the bosses and joining theconnecting blocks 32 are of a defined thickness and stiffness sufficientto guarantee the crown 31 a certain flexibility and thus to sufficientlyspread apart the bosses 33 in order to allow the collar 55 of the tube50 to pass when clipping the tube 50 onto the nozzle 3. Moreover, theconnecting branches 34 must have a thickness and height sufficient to besufficiently flexible and elastic and ensure that the bosses 33 matchthe shape of the glass tube 50.

According to the invention, the nozzle 3 will be made as one piece, forexample. The material used for producing the nozzle 3 will have to be ofa stiffness sufficient to guarantee that the tube 50 is held flatagainst the nozzle 3. Moreover, this material must not be aggressivewith respect to glass and must be able to be used in pharmacy.Polycarbonate is a material satisfying these different criteria.

The space separating the crown 31 from the cylindrical component 30, inwhich space the collar 55 is inserted, must be chosen in such a way asto guarantee that the annular surface 550, defined at the end of thetube 50, is held flat against the surface 301 of the cylindricalcomponent 30 and thereby guarantee a leaktight connection between thetube 50 and the nozzle 3.

According to the invention, when the pharmaceutical assembly 2 is fittedon the mechanical assembly to form the complete injection device 1, theleaktight connection between the tube 50 and the nozzle 3 is effected bythe compression of a seal 4 (FIGS. 2 and 4) integrated in the nozzle 3.

The functioning of such a needleless injection device 1 havingcomponents such as those defined in this application is described indetail in French patent application FR 2 815 544. The overallfunctioning of such a device 1 may, however, be summarized as follows:

At rest, a striker of the percussion device bears, for example, againsta stop with the aid of a pretensioned spring whose axis is more or lesscoincident with the axis of the striker. A maneuver on the part of thepatient releases the striker which, under the effect of the relaxationof the spring, will strike the primer situated on the same axis.Initiation of the primer then leads to ignition of the pyrotechniccharge of the gas generator. Under the action of the gases generated bythe pyrotechnic charge, the upstream piston plug 51 present in the tube50 of the container 5 is displaced and in turn pushes the activesubstance 53 in the direction of the injection system. The downstreampiston plug 52 is itself pushed until it comes to sit in the blind hole302 of the injection nozzle 3. Thus, the communication between theinside of the tube and the peripheral channels is formed and, as aresult, the active substance 53 can reach the peripheral channels 303and be ejected out of the device 1.

It will be obvious to those skilled in the art that the presentinvention allows embodiments in numerous other specific forms withoutdeparting from the scope of application of the invention as claimed.Consequently, the present embodiments are to be considered by way ofillustration and may be modified within the scope defined by theattached claims, nor need the invention be limited to the details givenhereinabove.

The following listing of claims will replace all prior versions, andlistings, of claims in the application:

1. An injection device comprising in particular an injection nozzle anda glass tube intended to receive an active substance to be injected,said tube being fixed to said nozzle with the aid of connecting means,the connecting means comprising at least three identical bosses whichare integral with the nozzle said bosses each comprising an inclinedpart which is terminated by a flange, said flange cooperating with acollar which is formed on the tube and is situated at one of the ends ofthe tube, said collar serving as a anti-return element for the tube whenthe latter is connected to the nozzle, said device being characterizedin that the bosses are connected to one another by connecting branches.2. The device as claimed in claim 1, characterized in that the inclinedpart of the bosses is inclined in the direction of the nozzle and towardthe inside of the nozzle.
 3. The device as claimed in claim 1,characterized in that each boss is inwardly curved, the bosses beinginscribed in a same circle whose diameter is substantially equal to theexternal diameter of the collar of the tube.
 4. The device as claimed inclaim 3, characterized in that the angle of opening defined by the twosegments joining the center of the circle to the ends of each inwardlycurved boss is between 17 and 23 degrees.
 5. The device as claimed inclaim 1, characterized in that the bosses are spaced apart from oneanother at regular intervals.
 6. The device as claimed in claim 1,characterized in that the nozzle has a flat surface, the bosses beingsituated at a non-zero distance from said surface the space between theflange of the bosses and said surface substantially corresponding to thethickness of the collar of the tube.
 7. The device as claimed in claim1, characterized in that the end of each of the bosses has a roundedshape.
 8. The device as claimed in claim 7, characterized in that thediameter of the circle is 13.2 mm, and in that the rounded shape has aradius of 0.1 mm.
 9. The device as claimed in claim 1, characterized inthat each boss is supported by a rod which is fixed to the nozzle and isable to deform elastically.
 10. The device as claimed in claim 1,characterized in that the connecting branches have a height of 1.4 mm.11. The device as claimed in claim 1, characterized in that the bossesare supported by the connecting branches, said connecting branches beingmade integral with the nozzle by means of connecting blocks and beingconnected to one another so as to define a substantially circular crownwhose diameter is substantially equal to the external diameter of thecollar (55) of the tube (50).
 12. The device as claimed in claim 11,characterized in that the nozzle, the bosses, the connecting branchesand the connecting blocks are made as one piece.
 13. The device claimedin claim 12, characterized in that the piece is made from polycarbonate.